The invention described herein was made in the course of, or under Contract No. EY-76-C-02-2676 with the Energy Research and Development Administration.
Conventionally, in carrying out a chemical reaction in which a gaseous reactant feed and steam are required, these components are mixed with the steam already in the evaporated state.
This is typified in the arrangement shown for the process for transporting chemically bound energy described in the article "Transport of Nuclear Heat by Means of Chemical Energy" by Kugeler et al [Nuclear Engineering and Design, Volume 34, No. 1, page 65 (1975)].
U.S. Pat. No. 3,958,625 to Wentorf, Jr., dealing with the same general subject matter as the Kugeler et al article discloses the premixing of water and gaseous reactants in a heat exchanger, the water and gas mixture being heated to about 350.degree. C. to produce a heated, pressurized gas and steam mixture for introduction into a reactor for the production of methane. Manifestly, the heating fluid utilized to perform the evaporation of the water is at a temperature far in excess of the boiling point of the water at the pressures employed.
It is the object of this invention to heat a gaseous reactant feed and a liquid in such a way as to produce a gas, vapor (i.e., the evaporated liquid) mixture utilizing a heating fluid at all times during the heat exchange at a temperature lower than the temperature required to boil the liquid at the prevailing total pressure. It is desired by this process to utilize the maximum possible amount of the heat available in the heating fluid.
A liquid is said to "boil" when it is heated to such a temperature that the vapor pressure of the liquid equals the applied pressure. Thus, at 100.degree. C. the vapor pressure of water is one atmosphere.